A spar is a sturdy pole—typically wood, metal, or carbon fiber—used in sailing rigging to support, extend, or control sails. Common examples include masts, booms, yards, and spinnaker poles, which are essential for maintaining sail shape and managing structural loads.

Key Types of Spars:
Mast: The vertical spar that supports sails and standing rigging.

Boom: A horizontal spar attached to the foot (bottom) of a sail.

Gaff: A spar that supports the top edge of a fore-and-aft sail.

Yard: A horizontal spar used to support square sails.

Bowsprit: A spar extending forward from the bow of a ship.

Spinnaker Pole: A pole used to extend the clew of a spinnaker sail.

Functions and Characteristics:
Structure & Control: By adjusting the tension and position of spars, sailors optimize sail shape for different wind conditions.

Rigging Support: Spars act as the primary structural framework for the sail plan.

Material: Traditionally made of wood, modern spars are often made of aluminum or carbon fiber for strength and reduced weight.

In addition to primary sailing functions, the term "spar" was historically used to describe spare poles stored on deck.